1. Field of the Invention
The present invention relates to a cover structure for an internal combustion engine.
2. Description of the Related Art
In general, a protrusion portion protruding toward an engine main body is provided on the inner surface (rear surface) of a chain case that covers a timing chain for transferring the rotation of a crank shaft of an engine to cam shafts.
For example, Patent Document 1 (JP 2002-130051 A) discloses an invention wherein there is provided a plurality of central fastening portions that are formed, such as to protrude from the inner surface of a chain case, struck against an engine main body, and fastened by bolts, and there are also provided connection portions that are formed such as to protrude from the inner surface of the chain case, make connections between the central fastening portions, and are struck against the engine main body.